The present invention relates to ink jet printing apparatus employing a plurality of printing modules. More particularly, the invention relates to calibrating the distance between pens in the pen scan direction (Y), and calibrating the displacement of nozzle arrays relative to each other in the print media index axis (X).
Color ink jet printers are described in the August 1988 issue of the Hewlett-Packard Journal. In addition, the following U.S. Pat. Nos. disclose ink jet printing technology: 4,709,245, M. J. Piatt, "Ink Jet Printer for Cooperatively Printing with a Plurality of Insertable Print/Cartridges"; 4,709,246, M. J. Piatt et al., "Adjustable Print/Cartridge Ink Jet Printer"; 4,709,247, M. J. Piatt et al., "High Resolution, Print/Cartridge Ink Jet Printer"; 4,709,248, M. J. Piatt et al., "Transverse Printing Control System for Multiple Print/Cartridge Printer"; all issued Nov. 24, 1987.